A huge 19th century steamship has been exerting a fascination on divers from its resting place off Kalkan in Turkey. Mark Ellen, Editor of WORD magazine, is one of those who has found its mysterious charms impossible to resist

For four thousand years ships have been crashing into the Kalkan reef. The seabed is littered with the remains of trade vessels that ploughed past this remote Turkish village and all of them met the same fate: they were lifted up by a tempest and dropped on a ridge of rock only 4.5m below the surface, their contents spilled onto the ocean floor. And you can still see all the evidence - anchors, rusting iron rudders, chunks of rotting superstructure from boats as old as the 5th century. Most of all you see the amphoras, fragments of the giant urns used to carry olive oil and wine right up until the 1700s. They're everywhere. One of our divers picked up a twin-handled Greek jug at 25m and waved it above his head like the FA Cup, and we all laughed so hard our masks filled up. It's amazing to think, when you pull a piece of broken pottery from a crack in the rock, that the last person who touched it was probably some wind-lashed Turk sailing to Alexandria with a cargo of house red. It's lain there undisturbed for 1500 years, its edges softened by the swell, until a bloke in a pair of bright red Speedos turns up with a tank strapped to his back. But the real prize in Kalkan is in 60m of water below a vast precipice of rock, a local legend so rich in mythology that it's a mind-blowing moment when you finally manage to find it. The remains of a steamship were discovered at 27m in the 1950s by sponge-divers, the kind who went down in those big metal helmets straight out of a Tintin adventure, air pumped down to them from a boat above. Its twisted grey ironwork is patrolled by solemn-looking groupers, and it's so badly damaged by the explosion when its engines hit the reef that it looks less like a wreck and more like a collection of body-parts scattered across the plateau of rock.

washed ashoreIntrigued by it all back in '94, Kalkan dive instructor Fatih Tunali got talking to a 90-year-old villager who remembered as a child 'a flash of flame and a deafening explosion' three miles offshore during a storm in around 1916. The bodies of some of the crew that washed ashore were buried in the hills with little ceremony. As no bow section had yet been located, Fatih figured that the wreck was only a fraction of the craft and began to scrutinise the surrounding area, soon finding a giant trough gouged into a steeply sloping rock face, presumably made by the keel of a large and heavily-laden vessel. He followed it down to 45m and saw a sight that he'll never forget. 'I was so excited I was shouting under water,' he told me. There was no name on the bow but when he found a ship's bell, and brought it to the surface by inflating his BC, it was engraved with the words 'Duchess Of York - Hull 1893'. So the mystery deepened. For a while it was thought that the two wrecks were part of the same vessel, that this was the missing bow section of the shallower wreck, but it's now widely believed that the bell was thrown into the deep by the blast and belonged to the smaller ship, identified by Lloyd's insurers as 'a 101.1ft single-deck iron-screw ketch' registered as the Duchess Of York and missing in World War One. Which implies that the deeper wreck is something else altogether. Recent evidence from the Turkish Navy Special Air Service suggests that it's the rusting remains of the Sakarya, a Turkish cargo ship carrying coal and chrome mine ore that sank after hitting the reef with engine trouble in the late '50s. Some of the cabins and a lot of machinery had been torn from the deck and its stern section has never been found, though it's likely to have sheered off on impact, slid 20m beyond the bow and dropped over another cliff edge to the ocean floor 300m below, a fantastic spectacle no scuba-diver will ever get to witness.

lunar landscapeThe Sakarya is not a dive for the faint-hearted. You drop down the anchor-chain to 12m and then thread out across the green and purple reef towards the precipice, its edges fringed with weed, its rock-face pitted like a lunar landscape. In its craters are dark orange starfish and little anemones that sprout from the end of thin white tubes and then fold back in like cocktail umbrellas when you pass them by. The whole panorama is breathtaking - if that's the right word when you're 20m under. Over to your right, the reef rises like a mountain range, like a Muppet Show of stone gargoyles showered with shoals of little purple fish. Metre-long tuna shimmer through the turquoise seascape, and occasionally barracuda cruise by like giant silver pike, hunting in packs. They flip their tails and dart sideways into a cascade of panicked blue jacks. And very occasionally there's a green turtle or the sinister head of a moray eel poking out of its bolthole. Transparent pink jellyfish float past you, lifeless apart from one tiny ticking membrane. The best sight of all is the rare glimpse of a flying gurnard, a 15cm freckled goby that sits still on the seabed until you get too close, then opens a vast fan-like pectoral fin ringed with electric blue and skims off like a butterfly. You drift out over a vertical wall dropping away to a fathomless blue gloom, then it's a 50m swim at the same level - wishing you had the stonking great fins of your dive guide - and the descent begins. Quite a feeling: the ceiling of the sea dissolves above you, yet nothing appears below. You drop 30m and see nothing at all, above or below. It's amazing how your air consumption shoots up when there is nothing on which to focus. There's just the strange, slightly uneasy sensation of being suspended in a vast wall of water. At 45m narcosis can play tricks with your sensibilities, and in my case it's true. What I take to be the giant face of the cartoon character Elmer Fudd emerging from the seabed is in fact the buckled railings of the shipwreck. My buddy's exhalations have turned into one giant bubble, quivering upwards like a jellyfish made of mercury, and when you find you're waving at your own reflection in a bubble it's probably best to snap out of it and concentrate on the job in hand.

slow motionAnd there it is, the bow section of this vast iron cargo boat, rolled over on its side, sleeping with the fishes. You slide down to 50m and examine the (now vertical) wooden decking, all rotted away save a few soft planks clinging to the metal frame. Inside you see the cargo, countless tons of coal and crumbling lumps of ore, great piles of it tipped out on the sand. It has to be said: this is not a welcoming sight. This is not a wreck that says 'come on in and pull up a chair'. Where the Duchess Of York up in the shallows is still lit by shafts of sunlight and seems warm and inviting, the Sakarya resides in the motionless green-blue twilight, cold and eerily quiet. Higher up, you can hear speedboats and there's a general sense of activity. Down here, the only sound is the echoey rumble of your own breathing. And at 60m there's a deathly stillness, just this sand-dusted ghost ship, the odd shoal of fish and a creepy-looking eel winding its way out of a porthole. Apart from the rust and decay, it's as though the accident happened yesterday, as everything is exactly where it fell five decades ago. You can imagine it happening, the ship careering down the cliff in slow motion, sections of it peeling away, breaking off and showering the seabed, the boiler-tanks flying across the water to where they sank 100m away. One of the metal masts lies beside it like a huge cigar tube, snapped at the top, its cables still attached. The hull is covered with ugly great gashes where it rammed the reef. The scale is simply mind-boggling: what kind of impact could leave a 5cm iron hull ripped apart like a sardine can? And it feels so deep down here. Your hands look white and withered by the pressure, as if you've been in a bath too long. As you drift past the giant anchor and the winching gear still bolted to the bow, you check your gauge - you've done 20 bar in three minutes. You wonder if the 140 left is enough for the crucially slow return. The mood lightens a touch when you look up to see your three fellow-divers standing on the ship in a cloud of freshly disturbed sediment. They are communicating in a kind of semaphore you'll never see in a BSAC manual. Two of them are playing imaginary whistles and one's giving you a cheery salute. Bless them. They're piping us aboard the Sakarya.

unresolved riddleThe ascent is magnificent. Every inch of the way the water's warmer and lighter, the air consumption less, and there's spectacular wreckage to examine. You trace your way back up the gully torn into the rock by the keel, still bristling with rusted plating, bolts and mangled lumps of metalwork. And, just to confuse the issue further, among all the debris are sections of twisted three-inch steam piping that must have been blown from the Duchess Of York. You turn for one last look and are amazed to find that you can see almost all of this great gothic barque, the ribbons of weed hanging from its bow rails, the rivets across its hull, the side section broken out like the skeleton of some vast prehistoric animal. The riddle of the ships' identities has yet to be completely resolved but we can't be far from the truth. You can imagine the Duchess Of York powering its way to Gallipoli with a cargo of coal in 1916, heading for Kalkan harbour to try to weather the storm and writing itself out of history for the next 78 years in a violent explosion that could be heard right along the coastline. And you can picture the Sakarya drifting helplessly towards the danger zone in around 1957, overloaded with coal and ore, smashing into the reef on the very same spot, snapping in two and descending to its silent and barnacled grave. The fact that neither ship was ever found again is purely magical, and that you can go down and see them even more so. Get out to Kalkan and watch this mystery unravel. Get there soon and, like us, you'll pretty much have the place to yourself.

Fatih Tunali runs a dive boat in Kalkan with regular visits to the Duchess of York and the Sakarya. His phone/fax is 0090 242 844 3955 and his website is www.dive-turkey.com